use proc_macro::TokenStream;
use proc_macro2::Ident;
use quote::{format_ident, quote};
use std::mem;
use syn::{
parse_macro_input, parse_quote, spanned::Spanned as _, AttributeArgs, FnArg, ItemFn, Lit, Meta,
NestedMeta, Type,
};
pub fn test(args: TokenStream, function: TokenStream) -> TokenStream {
let args = syn::parse_macro_input!(args as AttributeArgs);
let mut max_retries = 0;
let mut num_iterations = 1;
let mut on_failure_fn_name = quote!(None);
for arg in args {
match arg {
NestedMeta::Meta(Meta::NameValue(meta)) => {
let key_name = meta.path.get_ident().map(|i| i.to_string());
let result = (|| {
match key_name.as_deref() {
Some("retries") => max_retries = parse_int(&meta.lit)?,
Some("iterations") => num_iterations = parse_int(&meta.lit)?,
Some("on_failure") => {
if let Lit::Str(name) = meta.lit {
let mut path = syn::Path {
leading_colon: None,
segments: Default::default(),
};
for part in name.value().split("::") {
path.segments.push(Ident::new(part, name.span()).into());
}
on_failure_fn_name = quote!(Some(#path));
} else {
return Err(TokenStream::from(
syn::Error::new(
meta.lit.span(),
"on_failure argument must be a string",
)
.into_compile_error(),
));
}
}
_ => {
return Err(TokenStream::from(
syn::Error::new(meta.path.span(), "invalid argument")
.into_compile_error(),
))
}
}
Ok(())
})();
if let Err(tokens) = result {
return tokens;
}
}
other => {
return TokenStream::from(
syn::Error::new_spanned(other, "invalid argument").into_compile_error(),
)
}
}
}
let mut inner_fn = parse_macro_input!(function as ItemFn);
if max_retries > 0 && num_iterations > 1 {
return TokenStream::from(
syn::Error::new_spanned(inner_fn, "retries and randomized iterations can't be mixed")
.into_compile_error(),
);
}
let inner_fn_attributes = mem::take(&mut inner_fn.attrs);
let inner_fn_name = format_ident!("_{}", inner_fn.sig.ident);
let outer_fn_name = mem::replace(&mut inner_fn.sig.ident, inner_fn_name.clone());
let mut outer_fn: ItemFn = if inner_fn.sig.asyncness.is_some() {
let mut cx_vars = proc_macro2::TokenStream::new();
let mut cx_teardowns = proc_macro2::TokenStream::new();
let mut inner_fn_args = proc_macro2::TokenStream::new();
for (ix, arg) in inner_fn.sig.inputs.iter().enumerate() {
if let FnArg::Typed(arg) = arg {
if let Type::Path(ty) = &*arg.ty {
let last_segment = ty.path.segments.last();
match last_segment.map(|s| s.ident.to_string()).as_deref() {
Some("StdRng") => {
inner_fn_args.extend(quote!(rand::SeedableRng::seed_from_u64(_seed),));
continue;
}
Some("BackgroundExecutor") => {
inner_fn_args.extend(quote!(gpui::BackgroundExecutor::new(
std::sync::Arc::new(dispatcher.clone()),
),));
continue;
}
_ => {}
}
} else if let Type::Reference(ty) = &*arg.ty {
if let Type::Path(ty) = &*ty.elem {
let last_segment = ty.path.segments.last();
if let Some("TestAppContext") =
last_segment.map(|s| s.ident.to_string()).as_deref()
{
let cx_varname = format_ident!("cx_{}", ix);
cx_vars.extend(quote!(
let mut #cx_varname = gpui::TestAppContext::new(
dispatcher.clone()
);
));
cx_teardowns.extend(quote!(
dispatcher.run_until_parked();
#cx_varname.quit();
dispatcher.run_until_parked();
));
inner_fn_args.extend(quote!(&mut #cx_varname,));
continue;
}
}
}
}
return TokenStream::from(
syn::Error::new_spanned(arg, "invalid argument").into_compile_error(),
);
}
parse_quote! {
#[test]
fn #outer_fn_name() {
#inner_fn
gpui::run_test(
#num_iterations as u64,
#max_retries,
&mut |dispatcher, _seed| {
let executor = gpui::BackgroundExecutor::new(std::sync::Arc::new(dispatcher.clone()));
#cx_vars
executor.block_test(#inner_fn_name(#inner_fn_args));
#cx_teardowns
},
#on_failure_fn_name,
stringify!(#outer_fn_name).to_string(),
);
}
}
} else {
let mut cx_vars = proc_macro2::TokenStream::new();
let mut cx_teardowns = proc_macro2::TokenStream::new();
let mut inner_fn_args = proc_macro2::TokenStream::new();
for (ix, arg) in inner_fn.sig.inputs.iter().enumerate() {
if let FnArg::Typed(arg) = arg {
if let Type::Path(ty) = &*arg.ty {
let last_segment = ty.path.segments.last();
if let Some("StdRng") = last_segment.map(|s| s.ident.to_string()).as_deref() {
inner_fn_args.extend(quote!(rand::SeedableRng::seed_from_u64(_seed),));
continue;
}
} else if let Type::Reference(ty) = &*arg.ty {
if let Type::Path(ty) = &*ty.elem {
let last_segment = ty.path.segments.last();
match last_segment.map(|s| s.ident.to_string()).as_deref() {
Some("AppContext") => {
let cx_varname = format_ident!("cx_{}", ix);
let cx_varname_lock = format_ident!("cx_{}_lock", ix);
cx_vars.extend(quote!(
let mut #cx_varname = gpui::TestAppContext::new(
dispatcher.clone()
);
let mut #cx_varname_lock = #cx_varname.app.borrow_mut();
));
inner_fn_args.extend(quote!(&mut #cx_varname_lock,));
cx_teardowns.extend(quote!(
drop(#cx_varname_lock);
dispatcher.run_until_parked();
#cx_varname.update(|cx| { cx.quit() });
dispatcher.run_until_parked();
));
continue;
}
Some("TestAppContext") => {
let cx_varname = format_ident!("cx_{}", ix);
cx_vars.extend(quote!(
let mut #cx_varname = gpui::TestAppContext::new(
dispatcher.clone()
);
));
cx_teardowns.extend(quote!(
dispatcher.run_until_parked();
#cx_varname.quit();
dispatcher.run_until_parked();
));
inner_fn_args.extend(quote!(&mut #cx_varname,));
continue;
}
_ => {}
}
}
}
}
return TokenStream::from(
syn::Error::new_spanned(arg, "invalid argument").into_compile_error(),
);
}
parse_quote! {
#[test]
fn #outer_fn_name() {
#inner_fn
gpui::run_test(
#num_iterations as u64,
#max_retries,
&mut |dispatcher, _seed| {
#cx_vars
#inner_fn_name(#inner_fn_args);
#cx_teardowns
},
#on_failure_fn_name,
stringify!(#outer_fn_name).to_string(),
);
}
}
};
outer_fn.attrs.extend(inner_fn_attributes);
TokenStream::from(quote!(#outer_fn))
}
fn parse_int(literal: &Lit) -> Result<usize, TokenStream> {
let result = if let Lit::Int(int) = &literal {
int.base10_parse()
} else {
Err(syn::Error::new(literal.span(), "must be an integer"))
};
result.map_err(|err| TokenStream::from(err.into_compile_error()))
}